Lindens, trees of the genus Tilia, have insects—especially bees and bumblebees—as their main pollinators, attracted by the intense fragrance emanating from their flowers.
A new investigation reveals that this was the case as far back as the Cenozoic, about 24 million years ago (late Oligocene). In an article published in the journal New Phytologist, scientists from the University of Vienna (Austria), in collaboration with other researchers from Germany and the United States, say they have found fossilized linden flowers and bumblebees at the same site in the German state of Rhineland-Palatinate, in the southwest of the country. Furthermore, they reveal they have also found evidence of pollination interaction between both at the same site.
Using ultraviolet filters, the team detected pollen grains in the fossilized remains of the bumblebees. Then, with the help of advanced imaging techniques and electron microscopy, they identified them as belonging to linden trees, indicating that numerous bumblebees visited linden flowers shortly before they drowned in a lake within an ancient volcanic crater, resulting in their fossilization.
The linden species in question had been unknown to science until now, having been given the scientific name Tilia magnasepala. Two new extinct species of bumblebees were also documented: Bombus (Kronobombus) messegus and Bombus (Timebombus) paleocrater.
“This is the first time anywhere in the world that a fossil of a flower and its pollinating bees have been described from the same sediments and directly associated with one another using pollen,” says Christian Geier, the article’s first author, in a statement.
“This study has great potential to deepen our understanding of pollinators of the past,” the authors contend.
